Long exposure gives life to your shots; it allows you to show motion on a static image.
I was staring at the clouds passing gently in the summer sky, and I wanted to do a long-expo time-lapse. I took 15 snapshots of 30 seconds long exposure, for a 450 secs aggregate.
(from top left corner to bottom right)
And the light breeze turns into a strong wind gust.
PHOTOSTALK 